Radial turbines, which are operated in a known way with compressed air and which have a hollow shaft that carries the bell-shaped plate and that rotates in an air bearing, are used for driving the bell-shaped plate of such atomizers (DE 43 06 80, EP 0 796 663 B1). Air can either flow against the radial turbines in the tangential direction or through the turbines in the radial direction. In the latter case, the turbine wheel consists of a disk, which rotates in an essentially closed cylindrical interior of the bearing unit of the drive shaft and which has turbine blades formed on its end surface near the periphery. The driving air flows through the turbine blades in the radial direction within a channel, which is limited on one side by the turbine wheel and, in the known case, on its opposite side by a stationary part of the bearing unit. The driving air is guided into this drive channel through one or more supply channels, which open into a nozzle, whose opening, e.g., with a rectangular cross section, represents in the known case the smallest cross section of the associated driving-air supply. There is an air gap between the axial ends of the turbine blades and the stationary part of the bearing unit through which a portion of the driving air for the drive is lost. Another disadvantage is a turbulent boundary layer, which forms between the flowing driving air and the stationary housing part for the considered known radial turbine and causes high friction losses. Consequently, the efficiency of the known radial turbine is limited.